Chemical Bonding

• Chemical bonds - attractive forces that hold atoms together.

• Occur between valence electrons of different atoms.

• Two ways bonds form - transfer or the sharing of electrons.

• Purpose of bond formation - to fill the valence energy level of each atom (makes them stable)

• Two primary types of bonds - ionic and covalent.

Ionic Bonds

• Formed by - transfer of electrons to form ions.

• Opposite charged ions are electrostatically attrated to one another.

• Formed between metals and nonmetals.

Ionic Bonds 2

• Transfer of electrons - to have a full valence energy level.

• Metal - donate 1-3 electrons (cation)

• Nonmetal - accept 1-3 electrons (anion)

Ionic Bonds 3

• Once the cation and anion form, they will bond via electrostatic attraction.

Naming Ionic Compounds

1. The metal is written, first, the nonmetal, second.

2. The name of the nonmetal will be altered, the last syllable will be changed to end in 'ide'.

Writing Ionic Formulae

• Writing the chemical formula of ionic compounds using atomic abbreviations from the periodic table.

• Subscripts are used to denote how many of each atom is in the ionic compound.

1. Record the abbreviation of the metal, followed by the nonmetal.

2. Subscripts - determined by the charge of each ion - the overall charge of the compound must be neutral.

3. Subscripts go to the bottom-right of the atom they are assigned to.

Example 1:

Lithium + Chlorine

Li + Cl → Li⁺ + Cl^- → LiCl

Name: Lithium chloride

Example 2:

Barium + Oxygen

Ba + O → Ba²⁺ + O^2-→ BaO

Name: Barium oxide

Example 3:

Aluminum + Flourine

Al + F → Al³⁺ + F^- → AlF₃

Name: Aluminum fluoride

Example 4:

Sodium + Nitrogen

Na + N → Na⁺ + N^3- → Na₃N

Name: Sodium nitride